heartbroken- what am I supposed to do?

I am weeks away from delivering, maybe less, and just found out that my father in law died. We were supposed to see him tomorrow to celebrate his birthday. This man was my husbands hero. He idolized him like no other and I have no idea what to do. My 3 year old loved him so much too and of course I did too. He had a lot of health problems but this was still unexpected.  I still don't even know all of the details, just that he fell and my mother in law couldn't get him up.  My husband is a recovering alcoholic (has over 5 years sober) and I'm so worried that this is going to push him over the edge to relapse.  I don't know how to be there for him and keep things somewhat normal for my son not to mention the baby. Ugh this is hard.